Washington State L&I now requiring Arc Flash labels

[tom baker]

Today an electrician in Washington State had the AHJ require Arc Flash labels.
Our AHJ (Labor and Industries) has not required the labels until now, although I install them.
My guess is some one got hurt and a question was asked where are the Arc Flash labels?

 

[jcook980]

As a Washington PE, I have to ask...

Who is expected to do the calcs?

When are the calcs to be done?

Does this imply that all new installations in Washington will require arc flash studies and that failure to affix the labels will be considered cause for red tagging an installation?

I can see this generating a whole bunch of finger pointing as to who is responsible to do the calcs (contractor, owner, engineer). I haven't yet had a single client ask me to do an arc flash study.

If Washington expects the engineer to provide these calculations, the cost of my projects in Washington will have to go up.

 

[don_resqcapt19]

If Washington expects the engineer to provide these calculations, the cost of my projects in Washington will have to go up.

If I was an engineer, I wouldn't do them. With the major issue of getting "real" available fault current information from the utility, I would never sign my name to a calculation like that. Too much future liability. I expect that as soon as the professional liability insurance companies find this out, there will be a very expensive ridder to do this type of calcualtion.
Don

 

[ron]

Tom,
Could you clarify? Is the AHJ requiring the generic arc flash label required in the NEC, or the detailed calculation label recommended in the standard 70E.
NFPA 70E is not enforceable by the AHJ unless the local jurisdiction has adopted it as code, and I was not aware of any that have.

 

[dlhoule]

Well, here in Michigan we can get available fault current available from utility. Once you have that depending on what you are using for OCP you can plug a few numbers into a formula to come up with Arc Flash numbers. In many of our industrial facilities we have them on each piece of equipment.

Our labels show the hazard level and the required PPE.

I would think that if some one were to be killed or seriously injured, there would be some liability placed somewhere if they are not in place.

 

[don_resqcapt19]

Larry,

Well, here in Michigan we can get available fault current available from utility.

They may give you an available fault current, but utility systesms are too dynamic to give you a fault current that is suitable for use in arc flash calculations. The problem is that a lower available fault current often results in a higher incident energy level and requires a higher level of PPE. There is at least one utility that only provides worst case available fault current information and tells the user that the information is only for equipment selection and not suitable for use in arc flash calculations.
Don

 

[charlie b]

If I was an engineer, I wouldn't do them.

I am an engineer, and I don't plan to. My problem with this concept is that there are too many variables that can change the results, and over which I have no control. Also, I believe there are a number of possible field changes that could be made, without requiring my advanced review and approval (i.e., giving me a chance to redo the calculation), and that could invalidate my results.

By the way, Don, who did the arc flash calculation for your Avatar? :lol: :lol:

 

[jcook980]

Don,

That is what I am afraid of. We frequently work from worse-case assumptions of utility fault current and standard transformer impedances. If we did arc flash studies during design, they would be incorrect as we have little control over contractor selections for OCPD, transformer impedances, etc.

Jim

 

[dlhoule]

Slight misunderstanding on my part. I was thinking only of what comes after the service. Actually beyond substation in industrial facilities.

I am reasonably confident that by knowing type of breaker, fuses and so forth we can come up with a fairly good Arc Flash Calculation for the items beyond that point.

 

[coulter]

Guys and Girls -

I'm not seeing much of an issue here. There is risk in everything we do. Why is this one different?

JAO: The NEC requirement is a near useless label, required since the 2002. The real issue is the OSHA requirement for the workers to understand the risks.

If Washington expects the engineer to provide these calculations, the cost of my projects in Washington will have to go up

Yes - and ....?

...With the major issue of getting "real" available fault current information from the utility, I would never sign my name to a calculation like that...

Then I would ask, How do you meet 110.9 and 110.10? I'm not seeing a lot of difference.

...Too much future liability. I expect that as soon as the professional liability insurance companies find this out, there will be a very expensive ridder to do this type of calcualtion...

We are doing the calcs now and have been for a few years, and as far as I know there are no expensive riders yet. Then again, my crystal ball isn't nearly as sharp as yours, and tomorrow is a new day. But, what ever surcharge there is, jcook980 knows how to handle it - and so do I.

...Is the AHJ requiring the generic arc flash label required in the NEC, or the detailed calculation label recommended in the standard 70E.
NFPA 70E is not enforceable by the AHJ unless the local jurisdiction has adopted it as code, and I was not aware of any that have.

ron is absolutely right-on. The generic NEC required label is pretty benign. NFPA 70E is not law. It is however a useful standard and if followed, is an excellent defensible position.

... we can get available fault current available from utility. ...you can plug a few numbers into a formula to come up with Arc Flash numbers. ... Our labels show the hazard level and the required PPE...

Another great response. It meets my understanding of NFPA 70E, Annex D. The IEEE papers on arcflash are a little more complex than "plug a few numbers", but the concept is still right-on.

...The problem is that a lower available fault current often results in a higher incident energy level ...

I've heard this plenty, but I don't know where it comes from. I could see it if one used the term, "could possibly", instead of "often". Incident energy is porportional to I^2t. so if the current dropped to 70%, the clearing time would have to double to keep the same incident energy (NFPA 70E, Annex D, 600V example) Checking the upper and lower bounds and setting appropriate protective settings is necessary and certainly part of the engineering.

...If we did arc flash studies during design, they would be incorrect as we have little control over contractor selections for OCPD, transformer impedances

As I mentioned earlier: Why is this different than 110.9 or 110.10?

...Slight misunderstanding on my part...

I don't think so, I think you are right on

Some other engineers think there is too much liability - okay with me. As far as me doing the work - sure I would. Follow existing codes and standards. Do the research. State the limitations. Pay the insurance. Charge what the traffic will bear. Where is the difference from this to anything else we do?

carl

 

[jim dungar]

NFPA70, NFPA70E, and OSHA do not have any specific label verbage requirements. You are free to include as much or as little infomation as you want.

However regardless of what verbage is chosen, I would not want to explain why my label format did not correspond to a standard like ANSI Z535.

Also remember that arc-flash is only about 10 pages out of the entire 133 page NFPA70E Standard for Electrical Safety in the Workplace.

 

[tom baker]

Ron:
L&I is enforcing 110.16

 

[dlhoule]

L&I is enforcing 110.16


Who or what is L & I?

 

[charlie b]

"L & I" is the Washington State Department of Labor and Industries. They are the state-wide "AHJ" for almost anything related to employment issues.

 

[jcook980]

My question about who does the study and when still hasn't been answered.

Design studies are typically based on assumptions of infinite utility fault current, assumed transformer impedances, short conductor lengths, total motor contribution, etc. Therefore design calculated fault currents will be higher that the actual fault current. So we have ensured that interrupting rating of the equipment is "sufficient" (110.9) by making sure the equipment ratings are greater than the design fault currents.

110.10 is a little bit more of a problem as the design engineer does not know the actual impedance of the system that is ultimately constructed. We base our OCPD sizes based on the NEC but the actual coordination settings must wait until the equipment is selected. So we assume the most conservative settings to ensure that 110.10 is covered.

So, in an arc flash study at design would probably assume a higher than actual fault current and clearing times much shorter than actual. This will cause an inaccurate calculation of incident energy and inaccurate labeling per 110.16 which may force a level of PPE which is incorrect.

Obviously, the design studies need to be redone following equiment selection. But most clients feel that the design is finished when the bid documents are issued. We may be contracted to provide construction support but this is usually limited to RFI and submittal review.

So, to cover our clients (and ourselves, of course), should we including a spec section requiring the contractor to perform and submit a fault, coordination and arc flash study based on the actual installation?

 

[dlhoule]

IMHO Yes, The people servicing the equipment are much more apt to wear the proper PPE if they know the equipment is properly labelled. How do they know; you might ask. In many cases all they have to do is look at the OCP supplying the equipment.

 

[pete m.]

I might be headed down the wrong road here but..........

I believe that OSHA requires that electrical equipment be de-energized prior to working on it. I know that there are some instances that the equipment can be worked on energized by OSHA regulations as well.

That being said, why do we have a definition for "Qualified Person" in article 100?

If the person is truly "qualified" and had to work on a piece of energized equipment wouldn't he/she be asking about the arc-flash calc at that time prior to commencing with the work to assure that the proper PPE was utilized? If the study is done minutes before work begins I would think the accuracy of the incident energys, etc.. would be much greater.

The requirement to label equipment in accordance with 110.16 seems to me to be an insult to the "Qualified Person". :x

Perhaps along the lines of a certain fast food chain marking their coffee cups with "warning contains hot liquid"....?

 

[dlhoule]

Well Pete; In many industrial facilities where they are trying to follow OSHA regulations, they are also interested in keeping their down time to a minimum. Since a lot of troubleshooting has to be done with the power on it is helpful to know immediately what level of PPE is required.

 

[coulter]

My question about who does the study and when still hasn't been answered. ...should we including a spec section requiring the contractor to perform and submit a fault, coordination and arc flash study based on the actual installation?

Good response and still a good question. As a client agent, my inclination is to have the hired engineering firm make the protective relay/coordination and arcflash calcs. We however have sufficient technical expertise to understand the "law of unintended consequences" when changes get made.

But, you are talking about clients that don't have that expertise in-house and aren't willing to pay for it to stick around until the job is completed. For these clients I think your sugestion to spec as-built studies is excellent.

carl

 

[pete m.]

I understand what you are saying Larry . In todays society the dollar (down time) usually takes precedence over the electrician's safety.

I know we don't live in a perfect world but having seen burn victims and countless video presentations on arc-flash I just don't get it. Complacency seems to be another foe of the qualified electrician not only the almighty dollar. Sorry for the rant.